变高度薄壁箱梁剪力滞的几何非线性分析

根据势能变分原理,考虑薄壁箱梁翼缘的剪力滞效应和结构竖向挠度的几何非线性,导出了变高度薄壁箱梁的非线性控制微分方程,并采用样条最小二乘配点法进行求解.将计算值与试验结果进行了比较,两者吻合较好.研究表明,对于三跨变高度薄壁连续箱梁,在均布荷载作用下,内支座截面的应力分布不均匀程度较中跨跨中截面大;荷载越大,非线性效应越显著.

Geometrical Nonlinear Analysis of Thin-Walled Box Girder with Variable Height

Based on the variation principle of potential energy and considering the shear lag effect of stresses on flanges and the geometrical nonlinearity of vertical deflection of structures,the nonlinear governing differential equation was derived and solved by using the spline least square collocation method for thin-walled box girder with a variable height.The numerical simulation results are in good agreement with those obtained from experiments.The research shows that the distribution of stresses at the inner support is more uneven than that in the middle section of the middle span for a three-span continuous thin-walled box girder with a variable height under uniform distributed loads,and the nonlinear effectiveness becomes more obvious with the increase of load.